Support is sought to analyze existing videotaped data dealing with social interaction in 2-year-olds. Previous research has revealed that toddlers show an impressive number of social behaviors (e.g., smiling at a peer, offering a toy to a peer) in dyadic play. However, the objectives of this proposal are different from the approach taken in past research. Rather than looking at social behaviors in isolation, the proposed analyses focus on contingent interaction sequences. Thus the effect of social behaviors is observed by noting the number and type of contingent responses that emerge when one child initiates a social episode. Initially unacquainted pairs were filmed together in four sessions over a two week period. Multivariate procedures are proposed to analyze interactions within and over the four sessions. Factor analyses, utilizing social-personality data on each child, are also suggested to determine salient characteristics of pairs who were successful in forming positive social interactions.